/*
 * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package org.graalvm.nativeimage.c;

import java.io.PrintWriter;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.Collections;
import java.util.List;

/**
 * Defines the C header file for entry points enclosed by the annotated class or method.
 *
 * The {@code CHeader} annotation can be placed on methods and types: When placed on a method, this
 * method will be included into the defined header file. When placed on a class, all entry points in
 * that class (as well as the enclosing classes) will be included to the defined header file.
 *
 * @since 23.0
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
public @interface CHeader {

    /**
     * Class that defines the header file properties.
     *
     * @since 23.0
     */
    Class<? extends CHeader.Header> value();

    /**
     * Container for Header file properties.
     *
     * @since 23.0
     */
    interface Header {
        /**
         * Name of the header file.
         *
         * @since 23.0
         */
        String name();

        /**
         * List that contains the {@code Class<? extends CHeader.Header>} instances that declare
         * dependencies of this header file.
         *
         * @since 23.0
         */
        default List<Class<? extends Header>> dependsOn() {
            return Collections.emptyList();
        }

        /**
         * Writes a preamble after the dependencies and before the list of included methods.
         *
         * @since 23.0
         */
        @SuppressWarnings("unused")
        default void writePreamble(PrintWriter writer) {
        }
    }

}
